Is the Earth a giant living organism as the Gaia hypothesis predicts? A new discovery made at the University of Maryland may provide a key to answering this question. This key of sulfur could allow scientists to unlock heretofore hidden interactions between ocean organisms, atmosphere, and land -- interactions that might provide evidence supporting this famous theory.

The Gaia hypothesis -- first articulated by James Lovelock and Lynn Margulis in the 1970s -- holds that Earth's physical and biological processes are inextricably connected to form a self-regulating, essentially sentient, system.

One of the early predictions of this hypothesis was that there should be a sulfur compound made by organisms in the oceans that was stable enough against oxidation in water to allow its transfer to the air. Either the sulfur compound itself, or its atmospheric oxidation product, would have to return sulfur from the sea to the land surfaces. The most likely candidate for this role was deemed to be dimethyl sulfide.

Newly published work done at the University of Maryland by first author Harry Oduro, together with UMD geochemist James Farquhar and marine biologist Kathryn Van Alstyne of Western Washington University, provides a tool for tracing and measuring the movement of sulfur through ocean organisms, the atmosphere and the land in ways that may help prove or disprove the controversial Gaia theory.

According to Oduro and his colleagues, this work presents the first direct measurements of the isotopic composition of dimethylsulfide and of its precursor dimethylsulfoniopropionate. These measurements reveal differences in the isotope ratios of these two sulfur compounds that are produced by macroalga and phytoplankton. These measurements (1) are linked to the compounds' metabolism by these ocean organisms and (2) carry implications for tracking dimethylsulfide emissions from the ocean to the atmosphere.

Sulfur, the tenth most abundant element in the universe, is part of many inorganic and organic compounds. Sulfur cycles sulfur through the land, atmosphere and living things and plays critical roles in both climate and in the health of organisms and ecosystems.

"Dimethylsulfide emissions play a role in climate regulation through transformation to aerosols that are thought to influence the earth's radiation balance," says Oduro, who conducted the research while completing a Ph.D. in geology & earth system sciences at Maryland and now is a postdoctoral fellow at the Massachusetts Institute of Technology. "We show that differences in isotopic composition of dimethylsulfide may vary in ways that will help us to refine estimates of its emission into the atmosphere and of its cycling in the oceans."

As with many other chemical elements, sulfur consists of different isotopes. All isotopes of an element are characterized by having the same number of electrons and protons but different numbers of neutrons. Therefore, isotopes of an element are characterized by identical chemical properties, but different mass and nuclear properties. As a result, it can be possible for scientists to use unique combinations of an element's radioactive isotopes as isotopic signatures through which compounds with that element can be traced.

"What Harry did in this research was to devise a way to isolate and measure the sulfur isotopic composition of these two sulfur compounds," says Farquhar, a professor in the University of Maryland's department of geology. "This was a very difficult measurement to do right, and his measurements revealed an unexpected variability in an isotopic signal that appears to be related to the way the sulfur is metabolized.

"Harry's work establishes that we should expect to see variability in the sulfur isotope signatures of these compounds in the oceans under different environmental conditions and for different organisms. I think this will ultimately be very important for using isotopes to trace the cycling of these compounds in the surface oceans as well as the flux of dimethylsulfide to the atmosphere. The ability to do this could help us answer important climate questions, and ultimately better predict climate changes. And it may even help us to better trace connections between dimethylsulfide emissions and sulfate aerosols, ultimately testing a coupling in the Gaia hypothesis," Farquhar says.

This study appears in this week's Online Early Edition of the Proceedings of the National Academy of Sciences (PNAS)

Comments

We are one. Let's respect each other. That doesn't just mean tolerate. It means allow that other point of view and hold that in high regard. Look for the samenesses and/or the differences and love one another right now. If you do want to make change, set an example and others will follow. Please don't proselytze.

If one looks at the Biosphere as a single living organism then one must also consider that it would need a way of reproducing itself. In that regard, Man is much like a specialized cell that makes up the internal organs in a animal body. Being given the ability of creative mind we have been assigned the task of creating technology and with that one day colonizing other planets in the solar system and beyond, in essence seeding the cosmos with the Biosphere insuring survival long after the parent planet is gone. In this reality the creative power of mind is a predetermined state of life and gives us no choice when it comes to expanding beyond the confines of the Earth. If the Biosphere with all its earthly creatures is a single living organism then the fact that we are thinking about this proves that it is sentiant by nature, ( Noosphere ).
1.Glass Steagal, 2.Fixed credit 3.NAWAPA, 4. The stars

A dying sun birthed our solar system and our planet produced us. That's the view of science; the depth of that interconnectedness may rest with this latest research or something in the future. The evidence to date is supportive of the Gia hypothesis, but some people will always believe the earth is flat.

The dichotomy between 'living' and 'dead' matter, between 'intelligence' and 'instinct' has proved to be of an essentially cultural nature and not without devastating outcomes. The same values propogated slavery, imperialism and war. Perhaps one day we'll reach a point at which we regard even the tiniest particles, photons for example, as living, interractive entities. I like many of the previous comments for the open-minded views expressed on this subject.

In a mystical experience, 39 years ago, I saw at once, above and below the "Checkered Pavement," the Chessboard that separates all life forms into their respective, fabricated, cloaked appearances - Kings and Pawns, and those ’twixt these two, yet all of the same Quintessence. The image was of a Living Energy that penetrated that Level of Squares, thereby, mystically connecting all things above and below - the Élan Vital.

I beheld a tremendous slow-motion, plasmatic electro-magnetic lightning show, an arborescent display of the One Universal Life Force, Self-divided amongst its Chessmen on the Board. I was not a part of it, only a Witness. I saw, below the Board, the Life Energy Entity, the Puppeteer, as it were.

He was hidden below the perceptions of the entities on stage, the Chessmen, who believed they were, and behaved as, the separate existences they were not.

The evidence given here is good that our planet can be considered a single living organism -- not "life as we know it," but close enough to qualify for that title.

But sentient? Perhaps in the literal sense (having senses), but not in the popular sense (having advanced intelligence -- more properly, "sapience"). I'm not aware of any evidence, and I certainly find none in the article, that the organism that is Earth has in itself any more intelligence -- that is, any more ability to make deliberate decisions -- than a tree.

Living organism are robots and the Earth is not an robot, therefore its not an living organism, ...just like fire breeds, eats, grows, and procreates, but its not an robot ...therefore its not an living organism. !!!

You all think this is plausible? Really? It defies reason, even on its surface. People are so separate for answers yet they won't go far enough to consider God as the "sentient" mind behind all life. Consider: how do inanimate molecules connect together in such a way that they have the ability to work in concert in complex ways. Structure is not the same as information, and cells contain information. Information can only come from a mind, and not randomness. The can only be one answer--there is a mind that created everything.

@ Christian;
Why do you put such limitations on God and how he may do things? It truly seems sinful to say that God must do things the way you say and that is it. Who is to say that God did create us and everything, but he did it in a way that is so far beyond our comprehension that everything that science has discovered is actual science. Maybe God likes science and used it in creating us. If God created the Big Bang and stopped their, wouldn't that mean that he created everything, even us?

A long time ago the Biosphere produced a single celled organism that was instrumental in producing the iron ore deposits that modern civilization rely on today. The biological process that created this resource was instrumental in creating the conditions for modern human civilization and will ultimately allow us to progress into building favorable environments off planet; For example, a human embryo has a predetermined sequence in its development that allows it to grow into its adult form. Like a human baby a biosphere grows up and one day wants to move away from home. Glass Steagal.

Earth used to seem so enormous that its resources were regarded as infinite. Sentient or not, our planetary biosphere is a relatively small, intimately interwoven world in which, unfortunately, those who continue to discriminate between living and non-living matter, viability and worthlessness etc continue to determine our economic, industrial, political and environmental futures.

In my location this now involves [coal or coal seam gas] mining at every available location regardless of food security issues or ecological impacts. Short term profit for the few against immeasurable losses for the many, both human and non-human.

what i like to know is when they started with this theory..for i have my own theory on this..and i been with it i am sure much longer..so kindly get in touch on my email plez.. this is most important..thanks

I love earth, I love nature, I love any animal and creature, and I admit Gaia theory is cool.

However, I think the topic discussed is useless, uninteresting.
If we stretch the definition of "sentient", or "alive", sure, we can say the Earth is alive and Gaia is an organism.

So what ? So we love Earth more? The topic is barely scientific. We love Earth more if we use proper real-life science and engineering to clean up the pollution, realise more efficient energy production and environment friendly towns.

Let's study more math, physics and Engineering, and live the Gaia theory to the philosophers.